In terms of #2, I'd argue "not proven" for anything other than what has been regularly rerun, in two separate regards:
1) Without having access to evidence backing the claim about Fremantle's holdings (such as a vault inventory), the fact that the claim there is second or third-hand at best (even without a questionable hand being one of those in question) makes a claim that there are definitely hundreds of additional master copies questionable.
2) At the same time, however, the fact that Mitt Dawson made a claim doesn't make it automatically so- apparently, he also made such a claim about production materials for the program that have since turned up, and, as someone involved in other aspects of lost media, one must take care with assuming all claims coming from the people involved with shows are accurate, as there have been cases of myths being spread by those in such positions.
Similarly, it's hard to say if the rerun evidence can be used as definite proof- note, for instance, how the Library of Congress's recent inventorying of Mark Goodson's donations has demonstrated runs of G-T programs that have never been rerun, or similar claims by some folk here (and ones who can be considered reliable on this subject) about programs long regarded as lost that were better preserved than previously believed.
As such, I suspect that, absent hard evidence turning up, that this is unresolvable on the basis of current information- and that things could change quickly, as the recent accounts concerning the preservation of Canadian game shows demonstrates.
